Method of manufacturing commutators



Oct. 14. 192.4. 1,511,277

- A. FROHNE METHOD OF MANUFACTURING COMMUTATORS Filed April '7, 1922 2 Sheets-Sheet. l

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Oct. 14. 1924.

A. FROHNE METHOD OF MANUFACTURING COMMUTATORS 2 Shoots-Sheet 2 Filed April 7, 1922 w. w. a r/ msulating material Patented Oct. 14, 1924.

ALBIN-FROHNE, OF CHICAGO, ILLINOIS.

AssIoNoR T0 AMERICAN FLYER MANUFAC- TURING COMPANY, OF CHICAGO, ILLINOIS, CORPORATION OF ILLINOIS.

METHOD OF MANUFACTURING COMMUTA'I'ORS.

Application, filed April 7, 1922. Serial No. 550,552.

To all whom it may concern:

Be it known that I,- ALBIN Fnormn, a citizen of Germany, residing at Chicago, Cook County, Illinois, having declared my intention of becoming a citizen of the United States, have invented certain new and useful Improvements in Methods of Manufacturing Commutators, of'which the following is a specification.

is invention relates to certain improvements in commutators for electric motors, generators, etc. In this connection it relates to a construction of commutator which is very well adapted for use in relatively small sizes, but the features of the invention are not limited to use in commutators of small size or any other particular size. The invention also relates to the method. by which the commutators are manufactured. In this connection, it may be stated in general that the invention has to do with certain manufacturing steps which are so related to each other as to make it possible to produce commutators of relatively small size in "an unusually expeditious and cheap manner, and with a greatly improved mechanical construction of the finished article, and in a form which is best adapted for use in service on the motor or generator.

'I will state at this point that the general type of commutator to which this invention relates includes a central or base block of such as fiber, upon which are mounted the commutator segments. the segments being held in place by flanging their end portions over the ends of the afore said block. The segments themselves must be completely disconnected from each other" electrically, and this necessarily includes a complete electrical disconnection of the flange portions also. When thesegments are mounted upon the base block as a unit and are thereafter disconnected by sawing them apart. this sawing operation must be such as to bring about a complete severance of all portions of the segments from each other.

According to previous commutator constructions and methods of manufacture. the severance-of the segments from each other has involved also a sawing apart of the flange portions; and in order to perform the entire severance operationexpeditiously and economically. by the same sawing operation as that which the flanges have been severed severs the body portions of the segments, so that the sawing has had to be carried down low enough to include the flanges and has resulted in a partial severance of the base block also. This has seriously weakened the very foundation of the commutator with consequent disadvantages.

The main object of the present inventionis to provide a commutator of such construction and arrangement that the segments may be mounted upon the base block as a unit, thus making it possible to perform this op eration in the most expeditious and economical manner, the segment element being so formed that when it is mounted upon the base. block and flanged over against the ends thereof, the various commutator segments may be disconnected from each other by a simple operation carried down only through .the thickness of the sheet metal from which the segments are made. it being unnecessary to cut into the-material of itself.

Another object in this connection, is to provide a commutator which when completed shall also be provided with points for convenient attachment of the electric .wires to the "arious commutator segment-s.

Another object of the invention relates to the provision of steps of a n'lanufacturing process so related to each other that the finished product may be very cheaply and perfectlv manufactured at a very small cost.

Other objects and uses of the invention will appear from a detailed description of the same. which consists in the features of construction and combinations of parts herethe base block inafter described and claimed.-

In the drawings:

Figure 1 shows a face view of sheet metal blank for-providing mutator segments;

Fig. 2 shows diagrammatically a simple die press and machine for forming the segment blank into circular form, the machine standing in the initial position and the blank being perfectly straight;

Fig. 3 shows a view corresponding to Fig. 2. with the exception that the male die has been forced down into the initial operation:

Fig. 4 shows aview similar to that of Fig. 3. with the exception that the quadrant dies have been forced home so as to com-- plete the circular forming operation;

a typical the com- Fig. shows a right angular view corresponding to Fig. 3, being taken on the line 55 of Fig. 3, looking in the direction of the arrows;

Fig. 6 shows a perspective view of the circular segment piece as it comes from the circular forming dies;

Fig. 7 shows a view of the circular segment block' with the base block set into place, both elements being set into a head pressing die which stands in the initial position;

Fig. 8 shows a View corresponding to Fig. 7, with the exception that the head pressing dies have been forced together so as to turn up the flanges on the commutator segments and cause them tobite into the base block;

Fig. 9 shows a perspective view of the commutator as it comes from the dies of *Figs. 7 and 8;

Fig. 10 shows an end view of a completed commutator after the segments have been sawed apart; and

11 shows a cross section corresponding to Fig. 10.

Referring first to Fig. 1, the blank 12 in cludes a body portion 13 having a width equal to the axial dimension of the commutator segments, together with a series of disconnected ears 14 on one side and another series of disconnected ears 15 on the other side. The ears 14 and 15 lie respectively opposite to each other. The ears'14 are separated by notches 16, and the ears 15 are separated by notches 17, and half notches 18 are formed adjacent to the end earsv 14, and other halfnotches 19 are formed adjacent to the end ears 15. These notches and half notches are of such shape and size that when the blank is formed intoa complete circle and the ears are turned inwardly, said ears will not come into contact with each other but'will be electrically disconnected. If preferred, a hole 20' may be formed ad- ]acent to the inner end of each of the cars 15, sald holes serving as convenient points of attachment for the wires to the completed commutator segments.

I Referring to Fig. 2 there is illustrated a lower semi-circular female die 21 having the flat top surfaces 22 upon which the 'blank 12 may be seated. An L-shapedlnale 1 die23 is provided, the same havinga circula? sidewise projecting die block 24 of a size smaller than the size of the female die by an amount equal substantially to the thickness of the blank 12.

When the male die is forced down into the position shown in Fig. 3, the central portion of the blank is formed into semi-circular shape, so that the blank as a whole assumes a U-shape.

Slidably mounted with respect to the female die 21 is a pair of companion quadrant indicated in Fig. 4.

Fig. 8.

dies 25 and 26, each of which has a quadrant die surface 27 of substantially the same curvature as that of the female die 21. These quadrant dies 25 and 26 may be forced towards each other by means of the wedge blocks 28 and 29- which may be forced down avardly by reason of the slots 30 and 31 within which they operate.

While the male die 23 is retained in the lowered position of Fig. 3, the wedge blocks 28 and 29 are forced downwardly so as to force the quadrant dies towards each other, and thus bend the upper portions of the blank over the top surface of the circular portion 24 of the male die. This is clearly After this pressingoperation has been completed the dies are re leased and the circular segment blank may be slipped off of the circular die 24 and it will be found to have assumed the general form shown in Fig. 6.

The circular body block 32 mayt-hen be set into place within the central portion of the circular segment member. This body block 32 is preferably made of fiber or other insulating material having a proper mechanical strength and toughness. It is also preferred that the body block be made of a series of 'laminations stacked together upon each other as shown in Figs. 7 and 8, since by so doing the grain of the different laminations may be caused to lie. in different directions, so that the ultimate strength of the completed commutator will be correspondingly improved.

Examination of Figs. 7- and 8 shows that the body block 32 is of substantially the same axial dimension as the width of the body portion 13- of the commutator, or is slightly greater than said dimension.

After the body block has been set into the circular segment member, the assembled unit may be set onto the heading die 33 as shown in Fig. 7. This heading die has on its upper surface an annular recess 34 which receives the commutator lugs 14 and 15, as the case may be. A companion die 35 is located above the" die 33 and is alsopmvided with an annular recess 36 which is adapted to receive the lugs 15 or 14 as the case may be. A floating ring 36 is placed around the segment member to prevent the same from spreading. When the two dies are forced towards each other the lugs are flanged over as shown in Fig. 8, and are caused to bite into the material of the body block, as is clearly shown at 37 and 38 of Consequently, the parts are very securely locked together.

When the commutator, completed to this stage is removed from the 33 and 35, it wi-ll'have the general appearance shown in Fig. 9. It will then be provided with a single slot 39 at the point where the ends of the commutator memlber approach each tator to be made therefrom,

other. It may then be cutat the points 40 and 41 so as to sever the body portion 13 into three commutator segments 42. 43 and 44. This is clearly indicated in Figs. 10 and 11.

It will be observed from comparison of Figs. 9, 10 and 11 that in order to completely sever the commutator segments from each other it is only necessary to cut down through a thickness equal to the thickness of the metal of the origi nal blank, since the flange portions of the segments are already disconnected by the presence of the notches 16 and 17. It is therefore possible to complete the severance of the commutator segments by a sawing operation conducted in a direction parallel to the axle, and which sawing operation may be terminated without having to be carried into the material of the body block 32.

Examination of Figs. 9 and 10 shows that the perforations 20 come substantially at the proper points for convenient attachment of the wires to the commutator segments. If desired, the hole 45 may be drilled after the assembly operation is completed, or it may be provided in the original body block before insertion into the circular segment member, as shown in Fi s. 7 and 8.

While I have herein shown and described only a single embodiment of my present invention, which embodiment includes three commutator segments, still it will be understood that as far as the features of the invention are concerned, the number of segments might be either greater or smaller as the case may be. Therefore, Ido not limit myself to the embodimentherein disclosed except as I may do so in the claims. 1 claim: 1. The method of manufacturing electric commutators which consists in first prepare ing a metalblank having a length substantially equal to the circumferential dimenfrom and an overallwidth greater than the axial length of the completed article, and having oppositely disposed U-shaped notches in the twosides of the blank at positions corresponding to the locations of the gaps between the segments of the commuserving to establish oppositely disposed lugs in the two sides of the blank corresponding in position to the segments of the completed commutator. there being a perforation in each lug at one side ofthe blank, and which consists in thereafter subjecting the blank to die forming operations to bring it into cylindrical form with its ends separated a distance to establish one gap between the end segments, thereafter inserting a series -of circular laminations of fiber or' the like into the central portion of the cylinder so produced to establish a body block therein sion of the commutator to be made there-- having an axial dimension substantially equal to the axial dimension of the completed article, thereafter flanging the aforesaid lugs over against and into the material of the end portions of said body block so produced to cause them to bite into said material in a firm manner, and thereafter sawing straight across the blank axially and from a notch at one end to the correspond ing notch at the other end, to thereby completely sever the blank into electrically distinct segments without substantially cutting the body block and without the need of cutting the blank at points opposite to the ends of the body block, substantially as described.

2. The method of manufacturing electric commutators which consists in first preparing a metal blank having a length substan tially equal to the circumferential dimension of the commutator to be made therefrom and anorerall width greater than the axial length of the completed article, and having oppositely disposed notches in the two sides of the blank at positions corresponding to the locations of the gaps between the segments of the commutator to be made therefrom, serving to establish oppositely disposed lugs in the two sides ofthe blank corresponding in position to the segments of the completed commutator, and which consists in thereafter forming the blank into cylindrical form with its end separated a distance to establish one gap between the end segments, thereafter inserting a body block into the cylinder having an axial dimension substantially equal to the axial dimension of the completed article, thereafter flanging the aforesaid lugs over against the body block so as to cause them to bite into the material thereof in a firm manner, and thereafter sawing straight across the blank axially and from a notch at one end to the corresponding notch at the other end. to thereby completely sever the blank into electrically distinct segments without substantially cutting the body block and without the need of cutting the blank at points opposite to the ends of the body block, substantially as described.

3. The method of manufacturing electric commutators which consists in first preparing a metal sheet having a length substantially equal to the circumferential dimension of the commutator to he made therefrom and an overall width greater than the axial length of the completed'article. and having oppositely disposed notches in the two sides of the blank at positions cor respor ding to the locations of the gaps be tween the segments of the commutator to be made therefrom serving to partially sever ti e blank at positions corresponding to the gaps between the segments of the completed commutator, and which consists blank over against the end portions of the in thereafter bringing the blank into cybody block, and thereafter severing the malindrical form and inserting a body block terial of the blank at points in alignment 10 into the same, said body block having an with the notches aforesaid, substantially as axial dimension substantially equal to the described.

axial dimension of the completed article,

thereafter flanging the side portions of the ALBIN FROHNE. 

